The demand for solid surface countertops such as granite, marble, engineered stone, and Corian® has steadily risen over the past decade. As the demand for solid surface countertops, vanities, tub-decks, fireplace mantles and hearths continues to grow, it becomes more imperative for solid-surface fabrication companies to work faster, without sacrificing quality, in order to meet this demand. In working with solid surfaces, it is often desirable to join two or more pieces of material together, especially at the visible edges of countertops. By joining pieces together, it is possible to make the finished countertop appear thicker, and to provide a more substantial edge for the application of more elegant edge treatments. For example, much of the granite on the West Coast of the United States comes in slabs that are only about 20-mm thick. In order to make the countertop appear thicker, a manufacture can laminate a narrow strip of the slab to all visible edges, which makes the slab appear to be twice as thick. Other options are miter cutting the edge of the slab (i.e., a 45-degree cut) and miter cutting a narrow strip of material (known as the drop skirt), and then attaching these two pieces with adhesive. The process of joining material is a regular and necessary task for most solid-surface fabrication companies. Unfortunately, because this industry is still relatively young, the technology and tools used to join these materials are quite crude.
Solid surface material is often sold in slabs, which, in the case of granite, may be up to 9 feet by 6 feet in size, and in some cases, even larger. Solid surfaces may also be sold in tile form. These tiles are often available in standard sizes, such as 12″×12″, 16″×16″, or 18″×18″. It will be appreciated that solid material may be available in a variety of sizes, and may represent either a natural or man-made material.
Standard f-clamps are the most common tool employed by solid surface fabricators for joining two materials along 45 degree mitered cuts. There are many problems associated with using f-clamps, including the time it takes to use them, recurring replacement costs, poor joining quality, and the complications of setting them correctly. For example, when joining two miter-cut pieces, the current state of the art requires that the solid slab be placed finished-side-down and the drop skirt is installed extending vertically and upwardly away from the slab. Adhesive is placed in the seam between the two pieces and sets of clamps are then used to fix the drop skirt's position to the slab, while the adhesive cures. One such clamp system for joining miter-cut pieces is the Integra Mitre System, manufactured by Integra Adhesives, Inc. located in British Columbia, Canada.
The current art, however, has several shortcomings. First, the slab must be flipped with the finish-side-down, prior to installing the drop skirt. For larger pieces, this would require more than one person, thus increasing labor costs. Also, the slab may be damaged from too much handling, especially because the finished side is now in contact with a work surface at the manufacturing plant. As a result, the standard protocol is to flip the drop skirt complex back to the finished-side-up orientation, and then re-polishing areas that were damaged—greatly increasing labor costs. Second, each f-clamp must be tightened to approximately the same torque as all the others. Even small differences in compression may result in a poor adhesion, or in an uneven and unsightly seam. Third, it takes a long time to apply all the f-clamps and often requires more than one person to tighten all the f-clamps before the adhesive begins to cure. Fourth, as the f-clamps are tightened, the glue, epoxy, or other adhesive may be squeezed from between the pieces. This adhesive is, by nature, sticky and difficult to work with, and permanently hardens during the curing process. In this way, the screw threads on the f-clamps may get contaminated with the adhesive, rendering them inoperable and thus requiring recurring replacement costs. Fifth, there is also an increased risk of repetitive motion injuries due to the high number of clamps and the force required to tighten each clamp manually by hand. And finally, because the slab is finished-side-down during fabrication, the joint seam is not visible to the manufacturing operator unless that operator squats and looks up at the seam. This makes it extremely cumbersome and time consuming to apply and adjust the clamps to ensure a high-quality, strong and consistent joint.
What is therefore needed is a miter clamp that overcomes these deficiencies in the prior art.